Apparatus for producing a bus bar covered with an elastic sleeve



Oct. 19, 1965 R. APPARATUS FOR W. THOMAS PRODUCING A BUS BAR COVEREDWITH AN ELASTIC SLEEVE Original Filed June l5, 1960 United States PatentO 3,212,177 APPARATUS FOR PRODUCING A BUS BAR COVERED WITH AN ELASTICSLEEVE Robert W. Thomas, St. Clair Shores, Mich., assigner to I-TECircuit Breaker Company, Philadelphia, Pa., a corporation ofPennsylvania Original application June 13, 1960, Ser. No. 35,827.Divided and this application May 15, 1963, Ser. No. 280,632

3 Claims. (Cl. 29-235) This application is a divisional application ofmy copending case S.N. 35,827 filed June 13, 1960, now a'bandoned,entitled Method for Producing a Bus Bar Covered With an Elastic Sleeve.

This invention provides a novel procedure for quickly and easilycovering a flat or irregularly shaped bus bar with a sleeve of flexiblematerial which is snugly fitted thereto.

Most applications of bus bars is electrical structures, especiallyelectric distribution duct, require insulating means between the busbars and the steel structural members as Well as between bus bars. Forthe most part the bus bars have been insulated by utilizing tape whichwas wrapped around the bus fbars or by utilizing over sized tubes whichwere subsequently shrunk on to the bus bar. Still another methodcomprises extruding the insulation directly on the bus bar in a mannersimilar to the method used for insulated wire.

In the electric distribution duct described in detail in the l. B.Cataldo copending application Serial No. 7,810 filed February 10, 1960,now Patent No. 3,012,218 entitled Bus Duct Having Stacked Bus Bars andassigned to the assignee of the instant invention, irregularly shapedbus bars are covered by a butyl rubber sleeve having `a thickwall.Existing methods for placing the bar in the sleeve were unsuccessfulsince the bar was not of uniform crosssection, It was necessary toexpand the cross-section of the sleeve to provide for easy entrance ofthe bus bar. The sleeve was either forced onto the bus bar by Wringersor by stretching the sleeve. This proved unsuccessful in productionsince the bus bar in question contained many irregularities.

The instant invention overcomes the previously noted disadvantages oftheprior art by providing a novel method which includes inflating thesleeve by subjecting the interior thereof to a pressure in excess of theexternal pressure. Thereafter, the insertion of the bus bar into theexpanded sleeve is a simple operation.

In greater detail the method consists of placing the bus bar in achamber which is opened at one end and is provided with a push rodextending through the other end at a sliding seal. The sleeve is thenplaced in an oversized cage which is in axial alignment with thechamber. One end of the sleeve is clamped over the open end of thechamber and the other end of the sleeve is sealed by a clamp.

High pressure air is then introduced into the chamber. This air entersthe interior of the sleeve causing it to stretch with this stretchingbeing confined by the cage. The stretched sleeve is of considerablylarger cross-sec tional area than the largest cross-sectional area ofthe bus bar. The plunger is then moved toward the sleeve driving the busbar into the sleeve. The plunger is With- 3,212,177 Patented Oct. 19,1965 ICC drawn and the high pressure within the chamber is reduced sothat the sleeve becomes deflated and is snugly fitted to the bus bar.

Accordingly, a primary object of this invention is to provide a novelprocess for covering an irregularly shaped member with a snugly fittingelastic covering.

Another object is to provide a novel method of this nature wherein theelastic covering is expanded to a size larger than the largestcross-sectional area of the member to be inserted therein.

Still another object is to provide a novel method for covering a bus barwith a closely fitted elastic sleeve wherein the sleeve is utilized toseal an open ended chamber containing the bus bar and high pressure airis introduced into the chamber to inflate the sleeve.

These as Well as other objects of this invention shall become readilyapparent after reading the following description of the accompanyingdrawings in which:

FIGURE 1 is a fragmentary perspective view of a bus bar.

FIGURE 2 is a fragmentary perspective view of an elastic sleeve whichwill cover the bus bar of FIGURE l.

FIGURES 3 and 4 are cross-sections of the bus bar of FIGURE 1 with thesleeve of FIGURE 2 mounted thereon.

FIGURE 5 is a plan view of the apparatus utilized for inserting the busbar of FIGURE 1 into the sleeve of FIGURE 2 in accordance with theteachings of the instant invention.

FIGURE 6 is a side elevation of the apparatus illustrated in FIGURE 5.

FIGURE 7 is a View similar to FIGURE 6 with the bus bar partiallyinserted into the inflated sleeve.

FIGURE 8 is a cross-section taken through line 8 8 of FIGURE 7 lookingin the direction of arrows 8 8.

Now referring to the figures, bus bar 10 comprises two laminates 11 and12 secured together by rivets 13. Each of the bus bars 11, 12 areprovided with offsets 15, 16, respectively, which cooperate to definepocket 17 adapted to receive a contact of a bus duct plug (not shown).Bus bar 10 is covered with an elastic sleeve 18 by a process to behereinafter described. In figure 2 sleeve 18 is illustrated in a relaxedcondition wherein the longitudinal passage 19 therethrough is smaller incross-sectional area than the cross-sectional iarea of the straightportions of bus bar 10 and is considerably smaller in cross-sectionalarea than the offset portions of bus bar 10. This insulation covered busbar construction is described in detail in the aforesaid copendingapplication Serial No. 7,810, now Patent No. 3,012,218.

The novel means for inserting bus vbar 10 into sleeve 18 is by firstinserting bus bar 10 into chamber 21 through the open end 22 thereof.The other end of chamber 21 is provided with a sliding seal 23 havingpush rod 24 extending therethrough so as to be operable externally ofchamber 21. Elastic sleeve 18 is then placed into cage 25 which isopened at both ends. Cage 25 is provided with a cover 26 hinged at 27,28 along one edge thereof and the other edge is provided with clips 29,30 to maintain cover 26 closed.

Cage 25 and chamber 21 are in axial alignment in closely spaced end toend relationship. When bus bar 10 is being inserted into cage 25, cagecover 26 is open.

The left end of sleeve 18 is stretched and fitted `over chamber 21 atits open end 22.

A sealing connection is then formed between sleeve 18 and chamber 21 atthe open end 22 thereof by utilizing a collar type clamp 32. The otherend of sleeve 18 extends beyond the right hand end of cage 25 and issealed by utilizing clamp 33.

Compressed air is then introduced into chamber 21 through air line 34.The compressed lair enters sleeve 18 causing expansion thereof to apoint Where stretching of the sleeve membrane occurs with thisstretching being confined by cage 25. As best seen in FIGURE 8, thecross-sectional area of the inflated sleeve 18 is considerably largerthan the cross-sectional area of bus bar at offsets 15, 16.

Push rod 24 is then moved to the right with respect to FIGURE 8 movingbus bar 10 to the right into the inflated sleeve 18. Push rod 24 is thenwithdrawn to the left and the pressure within chamber 32 is reduced toatmospheric level. This permits sleeve 18 to become deflated and 'snuglyfit bus bar 10.

While the process hereinbefore described caused the elastic sleeve `t-obe inflated by injecting high pressure uid into the interior thereof.This should not be construed as a limitation of the meaning of theclaims which utilize the terminology of inating the sleeve. This phraseis meant to cover not only the process of injecting high pressure fluidinto the sleeve but includes any process by which a pressuredifferential is established between the inside 'and outside of thesleeve such that the sleeve is caused to expand.

In the foregoing, I have described rny invention only in connection withpreferred embodiments thereof. Many variations and modifications of theprinciples of my invention Within the scope of the description hereinare obvious. Accordingly, I prefer to be bound not by the specicdisclosure herein but only by the appending claims.

The embodiments of the invention in which an exclusive privilege orproperty is claimed are defined as follows:

1. Apparatus for forming an assembly by placing a rigid elongated memberWithin a close fitting elongated sleeve -of elastic material; saidapparatus including an elongated chamber open at one end; Ia sealingmeans forming a closure for the other end of said chamber; an elongatedcage at said one end and axially aligned with said chamber; a rst clampmeans surrounding said chamber for sealing a rst end of the sleeve oversaid one end while said sleeve is in said cage; a second clamp means atthe end of said cage rernote from said chamber for sealing a second endof the sleeve Within said cage; 'a rod slidably extending through saidseal for moving said member from said chamber to said cage; and uidpressure means connected to said chamber for applying fluid underpressure through said chamber into the interior of the sleeve Withinsaid cage to expand the sleeve and facilitate entry of said member intosaid sleeve.

2. Apparatus as set forth in claim 1 in which the cage is provided withan openable cover extending along the length of said cage for a distancesucient to permit said rigid member to be inserted through said cover bymovement transverse to the longitudinal axis of said cage.

3. Apparatus as set forth in claim 2 also including means formaintaining said cover in closed position while said sleeve is expanded.

References Cited by the Examiner UNITED STATES PATENTS 710,817 10/02Stevens 29-235 X 2,293,426 8/ 42 Coberly 29-234 X 2,645,004 7/ 53 Dorner29--450 2,803,056 8/57 Brissey et al 29--235 WILLIAM FELDMAN, PrimaryExaminer.

MILTON S. MEHR, Examiner.

1. APPARATUS FOR FORMING AN ASSEMBLY BY PLACING A RIGID ELONGATED MEMBERWITHIN A CLOSE FITTING ELONGATED SLEEVE OF ELASTIC MATERIAL; SAIDAPPRATUS INCLUDING AN ELONGATED CHAMBER OPEN AT ONE END; A SEALING MEANSFORMING CAGE AT SAID ONE END AND AXIALLY ALINGED WITH SAID CHAMBER; AFIRST CLAMP MEANS SURROUNDING SAID CHAMBER FOR SEALING A SIRST END OFTHE SLEEVE OVER SAID ONE END WHILE SAID SLEEVE IS IN SAID CAGE; A SECONDCLAMP MEANS AT THE END OF SAID CAGE REMOTE FROM SAID CHAMBER FOR SEALINGA SECOND END OF THE SLEEVE WITHIN SAID CAGE; A ROD SLIDABLY EXTENDINGTHROUGH SAID SEAL FOR MOVING SAID MEMBER FROM SAID CHAMBER TO SAID CAGE;AND FLUID PRESSURE MEANS CONNECTED TO SAID CHAMBER FOR APPLYING FLUIDUNDER PRESSURE THROUGH SAID CHAMBER INTO THE INTERIOR OF THE SLEEVEWITHIN SAID CAGE TO EXPAND THE SLEEVE AND FACILITATE ENTRY OF SAIDMEMBER INTO SAID SLEEVE.